U.S. Pat. No. 5,325,815 incorporated herein by reference discloses a sifting device for pets to deposit their waste, and for a user to separate the waste from the pet litter for disposal. The device has three nestable sifting trays. Each tray has handles, sidewalls, and a base. The thickness of the tray steadily increases when going from the handles to the base. Each tray base defines openings therethrough. When stacked, the bottom surface of each upper-tray is in direct continuous contact with the top surface of the tray therebeneath. When two trays are stacked in the proper configuration, the openings do not overlap. This inhibits the litter from passing through the openings in the upper tray. To sift, a user lifts the top-most tray from the two bottom trays to expose the top-most tray grating. The top-most tray is shaken causing litter to fall through the grating while the pet waste stays in the top-most tray. Once the waste is disposed, the top-most tray is made the bottom tray of the two other nested trays. Failure to properly orient the top-most tray as the bottom tray, however, may lead to litter inadvertently spilling from the device via the grating.